1. Field of Invention
The present invention relates to a filter substrate, a display panel, and a manufactured method thereof. More particularly, the present invention relates to a color filter substrate, a liquid crystal display panel, and a manufactured method thereof.
2. Description of Related Art
The flat panels have gradually take the place of the CRTs as result of the developing trends for light, thin, short and small gadgets. Among various kinds of flat panels, the liquid crystal display (LCD) has become the mainstream in the marketplace for its excellent performances such as speed, contrast ratio, view angle, and so on. The LCD is ordinarily composed of a liquid crystal display panel (LCD panel) and a backlight module. The LCD panel includes a color filter (CF) substrate, an active device array substrate and a liquid crystal (LC) layer sandwiched between. The backlight module is used to provide the planar light source which the LCD panel requires.
Particularly, displaying performance of the LCD is dramatically influenced by the thickness of the liquid crystal layer. Hence, spacers will be employed between the color filter substrate and the active device array substrate for controlling precisely the thickness of the LC layer. The spacers can be classified into stick-type spacers, ball-type spacers and photo-spacers. A spreading apparatus used for spreading the spacers between these two substrates is required for tick-type spacers and ball-type spacers which tend to get lumped in shape, causing non-uniformity of thickness of the LC layer. And therefore, an additional spreading process is needed for uniform thickness of the LC layer, and production cost is increased accordingly. The photo-spacers which are fabricated by the photolithography process, however, are recently paid much attention to by the industry. The reason is that locations and height of spacers can both be controlled to obtain uniform LC layer thickness.
Generally speaking, the function of the spacers is to support the color filter substrate and the active device array substrate, so they are fabricated as solid cylinders. Furthermore, as large-scale displays develop, multiple spacers should be placed inside the dummy area around the outer area of LCD panel for uniform stress distribution between two substrates, in addition to the placing of spacers inside the display area of LCD panel for requirements of the assembling and cutting processes.
FIG. 1 is a cross-sectional view of a traditional large-scale LCD panel. Referring to FIG. 1, the LCD panel 100 includes an active device array substrate 110, a CF substrate 120, and a LC layer 130 disposed in-between. In addition to multiple spacers 140a disposed inside the display area 102 of LCD panel 100, there are multiple spacers 140b disposed inside the dummy area 104 of LCD panel 100 for evenly supporting the two substrates.
In the manufacturing process of large-scale LCD panel 100, the region in which the LC layer 130 is filled is defined by a frame 150, and then LC layer 130 is filled in this region via the one drop fill (ODF) process. After that, the active device array substrate 110 and the color filter substrate 120 are combined together to form the LCD panel 100. Since said ODF process is performed under vacuum condition, the LCD panel 100 needs to be taken out when its frame 150 is to be applied with heat for curling. Yet, the suddenly changing pressure leads to reduce the adhesive force between the active device array substrate 110 and the color filter substrate 120, thereby causing the problem on the edges of LCD panel 100, as shown in FIG. 1. Besides, positioning misalignment between the active device array substrate 110 and the color filter substrate 120 tends to occur as well. Hence, the yield of large-scale LCD panel 100 would be affected.